What is the most network tuners anyone has recorded with simotaniously on a pi 4? with Librelec?

Quote from NOLAguy

Since my WinTV QuadHD-usb tuner setup was a failure (I didn't notice it was just the PCI-E version that was supported in Linux) I've decided to go with Siliconedust Homerun connects. and Librelec on a Pi 4. I already have a Duo I used to use it with WMC, and would like to purchase a Quatro. I'll be using a USB 3, external hard drive. Will the Pi be able to handle the recording? I don't plan to use the Pi for viewing. I'll use a Linux pc for that. Will the USB3 HD handle 6 recordings and 1 viewing? Will I have to upgrade my network switch to gig switch?

I'd probably go for a GigE switch between the two tuners and the Pi 4B just to cover yourself with a bit of headroom.

Also - be aware 6 tuners can mean you can record and stream far more than 6 channels. Subchannels on the same RF frequency as the main station should only use one tuner (at least that's how DVB tuners work in TV Headend with an HD HR).

If you use a USB 3.0 Hard Drive for recording then you should be able to record many services simultaneously without hitting issues.

Personally I can attest to being able to record two OTA 1080i ATSC streams while watching another pre-recorded show using an older HDHomeRun Connect dual tuner with a Raspberry Pi 3 and LE 8.2.5.

From a quick look at the technical specifications section for the HDHomeRun CONNECT QUATRO it appears that the device has a "100 base TX high speed network" connection. As such a Gigabit Ethernet switch might not be necessary (at least for 4 streams), but will likely be needed since you are considering more than 4 tuners/streams.

I did some bandwidth math in the hardware selection section of my tutorial: Build a Cheap PVR using Raspberry Pi 3, LibreELEC, Kodi, Tvheadend, & HDHomeRun. In theory it should be possible to record four OTA 1080i ATSC streams concurrently using a "100 base TX high speed network" connection.

Quote from NOLAguy

Unfortunately I have never seen any tv back end app that could record multiple sub-channels with an ATSC tuner. I know it can be done with DVB tuners, but don't think it can be done with ATSC tuners.

Does TV Headend not do it? That's really surprising if that's the case. Someone needs to get coding!

AIUI there's no fundamental difference between ATSC and DVB in that regard (both use a single MPEG2 transport stream per multiplex/RF channel).

If you can't achieve it by tuning two services in TV Headend you should be able to by streaming the entire RF mux (which will be 19.2Mbs) to stream and record all the video and audio services ?